1. Field of the Invention
The present invention relates to rubber-N-methoxymethylated nylon reinforced rubber composites and more particularly to reinforced rubber composites obtained by melt-blending 100 parts by weight of a natural or synthetic rubber and 5-150 parts by weight of N-methoxymethylated nylon (degree of N-methoxymethylation: 10-40 mol%) in the presence of or in the absence of compounding agents, such as filler, antioxidant and the like in Banbury mixer and mixing thereto 5-20 parts by weight based on 100 parts of the above described nylon, of a higher saturated aliphatic monobasic organic acid of a cross-linking agent for N-methoxymethylated nylon, 0.5-20 parts by weight based on 100 parts of rubber of a vulcanizing agent for rubber and an appropriate amount of compounding agents and then effecting simultaneous cross-linking of the rubber and N-methoxymethylated nylon.
2. Description of the Prior Art
It has been publicly known that reinforced rubber composites are produced by mechanically blending well known reinforcing agents, such as carbon black, white carbon, light calcium carbonate, styrene resins, phenolic resins, melamine resins, petroleum resins, nylon resins and the like to a general purpose rubber and that by such means the mechanical properties of the general purpose rubber can be improved. However, it has been also known that the rubber composites obtained by such a general blending means do not necessarily show satisfactory physical properties. Particularly, among the physical properties of the rubber composites, the high Young's modulus or the creep strength is in inverse proportion to the tear strength and there has never been found the rubber composites in which these properties are balanced.
Namely, the previous process for improving on the high Young's modulus of the general purpose rubbers comprises mechanically blending the above described inorganic or organic rubber reinforcing agents to the rubber but it has been very difficult to highly improve the creep strength and the tear strength in addition to the high Young's modulus. The creep strength of the general purpose rubber materials is more than about 30% and the improvement of the creep strength has been demanded.
In the present rubber industry, inexpensive rubber composites having a high Young's modulus in which the above described inconsistent properties are satisfied, are demanded for production of industrial articles, for example tires, belts, hoses and the like.
Hitherto, as a unique material in field of materials having a high Young's modulus, urethane rubber has been known but urethane rubber is insufficient in the tear strength and is expensive and therefore the application is considerably limited.
Accordingly, in order to solve this problem of the improvement of these inconsistent properties, a development of reinforced rubber composites having a novel structure has been demanded.